North Korea Suspected of Preparing New Test

WASHINGTON, Oct. 16, 2006 — -- ABC News has learned that U.S. spy satellites over North Korea have picked up suspicious vehicle movements near the location of last week's nuclear test.

Officials told ABC News they cannot be sure what North Korea is up to but say it could be preparations for another nuclear test.

For several days, the North Koreans have threatened to conduct another nuclear test.

Secretary of State Condoleezza Rice departs Tuesday for Asia to "rally the support of our friends and allies" in the region. Asked today how concerned she was about indications of a possible second test, Rice replied, "We're watching it, obviously. ... I think it goes to say that that would further deepen the isolation of North Korea, and I hope they would not take such a provocative act."

The news comes on the same day that U.S. intelligence confirmed that North Korea did set off a small nuclear device last week. Air samples collected days after the blast proved the presence of radioactive particles.

North Korean officials had told China they were expecting the nuclear test would result in a yield of four kilotons. Today a statement by the director of national intelligence concluded the blast produced a yield significantly less than a kiloton.

The 200 tons of explosive power produced in the North Korean test is less than 2 percent the magnitude of the atomic bomb dropped on Hiroshima.

Some experts caution this should not take away from the fact that the North Korean test still produced a blast much bigger than any conventional bomb.

"If it were detonated in Washington, it would destroy several blocks," said David Albright of the Institute for Science and International Security.

But Albright said that North Korea could conduct further tests just to raise further American concerns.

"For a nation that wants to deter a country like the U.S., they have to have a significantly higher yield," he said.

In South Korea, today they were preparing for war. Wailing sirens sent people scurrying to underground bomb shelters. It was just a drill, but considering the latest developments, it was a drill with added urgency.

U.N. sanctions passed over the weekend are meant to force North Korea to abandon its nuclear program, but there are real questions about how they will be enforced.

China voted for the sanctions, but U.S. officials worry over how serious the Chinese are about making them work.

China's ambassador to the United Nations, Wang Guangya, told reporters today that China will inspect cargo from North Korea for illegal weapons and missiles but indicated that it will not stop and board ships to search for equipment or material that could be used to make nuclear, chemical and biological weapons or ballistic missiles.

"The question was raised whether China will do inspections. Inspections, yes, but inspection is different than interdiction and interception," Wang said. "I think different countries will do it different ways."